Different types of moveable barrier operators have been sold over the years and these systems have been used to actuate various types of moveable barriers. For example, garage door operators have been used to move garage doors and gate operators have been used to open and close gates.
Such barrier movement operators may include a wall control unit, which is connected to send signals to a head unit thereby causing the head unit to open and close the barrier. In addition, these operators often include a receiver unit at the head unit to receive wireless transmissions from a hand-held code transmitter or from a keypad transmitter, which may be affixed to the outside of the area closed by the barrier or other structure.
Barrier operators sometimes include the ability to determine the torque of the motor. The torque may be used in a variable speed motor to determine whether the barrier has reached an obstruction. In previous systems, the operator received information related to the torque of the motor by using a tachometer (or some other type of sensor or sensing device), reading the speed of the motor, and deriving the torque from the amount of speed reduction of the motor.
Positional information concerning the barrier may also be determined and used in operator systems, for example, to determine when to slow down the barrier as the barrier approaches a limit such as the ground. In previous systems, tachometers (or other types of sensors or sensing devices) were used to determine the position of the barrier. In one example, the number of tachometer pulses was measured from a limit or a pass point, in order to determine the position of the barrier.
Unfortunately, the above-mentioned previous systems required the use of an extra component, the tachometer, which significantly increased the cost of the system. In addition, when a tachometer was used, other additional circuitry and/or software were frequently required to allow this additional component to operate. Another problem associated with previous systems was that only certain types of sensors or sensing devices could be used with certain types of motors, so that the user could not easily change motor types. This lack of flexibility added to user frustration, for instance, when a certain type of motor was not available or too costly for the user.